In RAN3#57bis and RAN2#59bis meeting, statistical multiplexing is agreed as a requirement for EMBMS multiplexing operation. According to an existing mechanism for content synchronization, a gateway determines whether data packets are segmented and concatenated at Layer 2 (L2) based on a fixed transmission rate at an air interface. In the case of statistical multiplexing, the transmission rate at the air interface varies over time, such that the gateway cannot determine whether the data packets are segmented and concatenated or not. Thus, it is necessary to separate content synchronization from other operations, no as to design a solution for content synchronization as an independent system. Consequently, the existing mechanism for content synchronization cannot cooperate with statistical multiplexing. In order to cooperate with statistical multiplexing commendably and fulfill the delay/robustness requirements of EMBMS, the content synchronization mechanism design should be revised.
In [R3-071920 MBSFN scheduling and content synchronization, Nokia. Nokia Siemens Network, 2007-10], Nokia simply proposed a solution for content synchronization based on fixed burst length, which can cooperate with statistical multiplexing. However, some key points are not clearly described in this solution. Moreover, it requires significant control packets load to achieve a 1 second processing delay requirement. On the other hand, the control mechanism in the Nokia solution lacks flexibility. Additionally, it is discovered by simulation that there is only one choice of parameter setting applicable in the Nokia solution.
Therefore, there is a need for a solution of content synchronization capable of overcoming the above defects of the Nokia solution.
According to the present invention, an ALU suggestion is provided for content synchronization design, which is referred to as “window-based solution” and operates well with statistical multiplexing.